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Small yellow bugs on surface of container soil.

Posted by Sureshot2 none (My Page) on
Mon, Aug 11, 14 at 0:02

So for the past few weeks I've been seeing what appears to be gnats flying around near my plants, thinking they were fungus gnats I let my plants dry out and applied some imid. This didn't seem to do much and I'm still seeing these little things flying around. During this time I've also noticed my plant has not been looking very healthy, after a closer inspection I noticed these small yellowish/white elongated bugs crawling around on the surface, I figure they're about 1 to 1.5mm in length. They look too long to be root aphids and they don't look like springtails to me. After hours of searching I still cant seem to figure out what it is and how to treat it.

I have included a photo of one, sorry for the low quality, I had to use a magnifying glass !


Follow-Up Postings:

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RE: Small yellow bugs on surface of container soil.

It probably is time to change the soil these plants are growing in. The larva that hatch and grow in soils only do that in soils that are very close to being too wet for the plants, at least according to all of the horticulturists I have talked with tell me.


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RE: Small yellow bugs on surface of container soil.

Look up fungus gnat larvae to see if that's not your problem. Resolving existing fungus gnat infestations includes allowing the potting mix to dry out somewhat in between waterings ;applying a layer of food grade diatomaceous earth (DE) to the surface. It will eventually work its way into the medium, eliminating the soft bodied larvae.

Some people apply a thick layer of coarse sand in order to prevent the adults from laying eggs.

Rather than the imidicloprid (not the right choice) or other strong chemical, opt for Gnatrol or even dissolved pieces of mosquito dunks. Both contain Bacillus thuringiensis-israelensis, a naturally occurring bacterium which infects certain Diperans...like fungus gnats or mosquitoes.

Long term fixes include changing your potting mix for one that is faster draining (very coarse textured), or amending the potting medium with substantial amounts of perlite. Of course, toss the old stuff in the pot. And evaluate your watering practices. Fungus gnats require a very moist environment in order to thrive.


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RE: Small yellow bugs on surface of container soil.

I don't think it is fungus gnat larvae after close inspection, as these seem a little bigger and have legs on them, which makes me think they could possibly be thrips? . I have been letting my plant dry out but they still seem to come back. I will definitely look into the DE and get some mosquito dunks. I recently repotted the plant into a larger pot and replaced as much soil as i could but that didnt seem to help much either. The plant is chamomile, what would be a good potting mix to use for it ? Thanks again


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RE: Small yellow bugs on surface of container soil.

Oh darn.....I couldn'f focus on the image earlier. Totally NOT fungus gnat larvae! Don't worry about the dunks....they won't work.

It sure does look like a thrip nymph but perhaps a symphalid. Google to compare.


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RE: Small yellow bugs on surface of container soil.

Not a problem! After comparing the two it definitely looks to be the thrip nymph, which now raises my next question... Whats the best way to get rid of them ?

Edit: After more looking, it still appears that whats on the surface is thrips, but I am still seeing the occasional gnat looking bug flying around inside. Is it possible the two are totally unrelated?

This post was edited by Sureshot2 on Mon, Aug 11, 14 at 21:44


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RE: Small yellow bugs on surface of container soil.

Certainly possible, sureshot. Let me ask you this.....is it possible that the flying things are adult thrips. Some species flit around.

The DE mentioned earlier should be helpful in controlling the nymphs.


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RE: Small yellow bugs on surface of container soil.

I suppose that it is possible, I will try to get a close look and maybe get a picture of one so I can compare the two. I'll pick some up some DE if that will help.


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RE: Small yellow bugs on surface of container soil.

I suppose that it is possible, I will try to get a close look and maybe get a picture of one so I can compare the two. I'll pick some up some DE if that will help.


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RE: Small yellow bugs on surface of container soil.

Thrip larva and nymphs hatch and grow on plant leaves not in the soil. Any larva living in, or on, the soil probably is not a Thrip.


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RE: Small yellow bugs on surface of container soil.

That's not entirely correct, Kimmsr. Some species spend part of their life cycle in the soil.


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RE: Small yellow bugs on surface of container soil.

To me they look very similar to thrips, nothing else I've looked up looks similar. Today I noticed that they were also on the soil and around the base of my chives, which are not looking so healthy now. I took a photo as best as I could. I am not sure if the damage to the chives is being caused by these little pests or not.


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